July 2020
1. close SWTOR launcher and from task manager as well
2. Copy your already available Assets folder to steam/steamapps/common/star wars the old republic
3. Copy all .version extension files to the same steam folder
4. restart swtor on Steam (make sure to launch on Steam shortcut)
To see extensions you must enable extension option in Windows 10 control panel>folder options
Enjoy a great game!
August 2020
Does it work in reverse to go back to not using the steam version?
August 2020
Haven't heard of anyone who has tried to go back from Steam to Swtor but I would assume just do the opposite for going to steam.